We conduct observation and research on ground solar radiation using the international standard RAMSES spectrometers and CMP11 global solar radiometers for 8 cities (Ngari, Shigaze, Lhasa, Nyingchi, Chengdu, Wuhan, Hangzhou, Shanghai) along the 30°N latitude region of China during 2019 and 2020. Observation results show that along the 30 °N region in China, Tibet’s overall solar spectrum intensities are not only much higher than that of low altitude inland cities, but also the spectral curves are smoother and less absorbed than that at low altitude in terms of morphological characteristics. During the observation period, the maximum monochromatic solar spectral intensity on the ground in Tibet reached 2 018.48 mW·(m2·nm)-1 (Ngari, Jun.21, 2020), and the maximum monochromatic solar spectral intensity in other mainland cities at the same latitude is only 756.22 mW·(m2·nm)-1(Chengdu, Nov. 3, 2019); The ultraviolet spectra (280-400nm) contained in the ground solar spectra of Tibet is about 1.5 times higher than that of the low altitude in the mainland. The strong ultraviolet has a corresponding impact on the ecology and human health in Tibet; It is found that during the observation, the ground solar spectral intensity of Lhasa is about 1.5～1.7 times than that of Chengdu; The ground solar spectral intensity of Ngari is about 0.2 times higher than that of Shanghai. The observation results provide field solar spectral data for the utilization of solar energy resources and ecological environment research in the 30°N latitude region; We conduct observational studies synchronously to the solar spectrum of the solar eclipse during the summer solstice in 2020. It is found that the radiation energy loss in Lhasa and Ngari during the solar eclipse is more than 95%. The effects of atmospheric factors such as clouds and aerosols on the solar spectrum and total solar radiation are analyzed. The work shows that the global solar radiation value in Ngari and other places in Tibet frequently exceeds the solar constant during the summers.